Meningitis pt.3 Flashcards
What are the general signs and symptoms of meningitis?
Although different etiologies are possible, the signs and symptoms that the patient develops are often superimposable:
- Central: Headache and altered mental status
- Ears: Phonophobia
- Eyes: Photophobia
- Neck: Stiffness
- Systemic: High fever
- Trunk, mucus membranes, extremities (if meningococcal):
What is the most important test used to diagnose suspected meningitis?
Lumbar puncture
What information will a lumbar puncture provide diagnostically for meningitis?
Presence of meningitis and its etiology
What is a lumbar puncture?
Invasive procedure in which a needle is inserted into the spinal canal to allow the collection of cerebrospinal fluid for diagnostic testing involving CNS.
What is done to the CSF collected by a lumbar puncture?
- It is analyzed macroscopically and microscopically
- Generally includes a cell count, presence and types of white blood cells, and determination of the glucose and protein concentrations
- Other data can be collected such as opening pressure, presence of certain enzymes and metabolites, microbiology testing (such as gram staining), etc.
- Commonly, CSF will be tested with PCR to look for genetic traces of the possible etiological agent in cases of meningitis
What can lumbar punctures be used in the diagnosis of ?
- The most common purpose is in suspected meningitis
- In any age group, subarachnoid hemorrhage, hydrocephalus, benign intracranial hypertension, and many other diagnoses may be supported or excluded with this test
- It may also be used to detect the presence of malignant cells in the CSF, as in carcinomatous meningitis or medulloblastoma
What is procedure is recommended before a lumbar puncture?
An MRI or CT scan is recommended prior to lumbar puncture, particularly in severely ill patients
How long would PCR results take to come back for lumbar puncture samples? Significance?
About one hour, which is extremely important to start administration the correct therapy to the patient as soon as possible (meningitis is a very rapidly progressive disease)
How long would PCR results take to come back for lumbar puncture samples? Significance?
- About one hour, which is extremely important to start administering the correct therapy to the patient as soon as possible (meningitis is a very rapidly progressive disease)
- Rapid diagnosis of meningococcal meningitis (in 4-6
hours)
What other tests, aside from lumbar puncture, may be ordered in a case of suspected meningitis?
Other suggested tests include blood and urine culture, chest X-rays and CT of the head
What CSF finding would suggest acute bacterial meningitis?
Cloudy yellowish turbid (purulent) appearance, Low glucose, high protein, high # of cells (mostly PMNs, PMNs often more than 300 mm3)
What CSF finding would suggest acute viral meningitis?
Clear appearance , normal glucose (reduced in many viral infections (<40 mg/dl) such as in mumps), normal or high protein, presence of initially neutrophils;later mononuclear cells (mostly lymphocytes)
Which position is best during a lumbar puncture?
- The widest intersomatic space is obtained by putting the child in the sitting position
- In older individuals, the lateral recumbent position is preferred to obtain a more accurate opening pressure and to reduce risk of post puncture headache
What CSF finding would suggest tuberculosis meningitis?
Yellowish and viscous appearance, Low glucose, high protein,cells <300 mm3 Monuclear and PMNs (initially neutrophils, then lymphocytes)
What CSF finding would suggest malignant meningitis?
Low glucose, high protein, usually mononuclear cells
